SALT LAKE CITY — A man who saw himself as former Utah Attorney General Mark Shurtleff's "fixer" has been criminally charged in an ongoing investigation involving the state's two previous top law enforcers.

Timothy William Lawson, 49, engaged in multiple instances of retaliating against witnesses, witness tampering, obstructing justice, bribery, falsifying tax information to hide income and failing to pay taxes, according to felony charges filed Thursday in 3rd District Court.

Specifically, Lawson is charged with pattern of unlawful activity, a second-degree felony; two counts of tax violations, second- and third-degree felonies; retaliation against a witness, a third-degree felony; and two second-degree felony counts of obstruction of justice.

Lawson, of Provo, is a longtime friend of Shurtleff and his successor, John Swallow, who resigned as attorney general this month.

Prosecutors allege Lawson used that friendship to influence others using intimidation and aggressive tactics, mostly behind the scenes. He told one businessman that he was like "Porter Rockwell and that he took care of things" for Shurtleff, according to court documents. Porter Rockwell was known as LDS Church founder Joseph Smith's roughneck bodyguard.

At one point in March 2010, Kirk Torgensen, chief deputy of the attorney general's office civil division, sent an email to Shurtleff and Swallow — who then was chief deputy for the civil division — expressing concern about Lawson.

"Lawson is the guy that is going to bring down the house of cards," Torgensen wrote.

Police booked Lawson into the Utah County Jail on Thursday afternoon. He is held on $250,000 bail, said Utah County Sheriff's Sgt. Spencer Cannon. Investigators removed paper files from Lawson's home Thursday evening.

In February 2013, Torgensen took his concerns about Lawson to Davis County Attorney Troy Rawlings who, along with Salt Lake County District Attorney Sim Gill, opened an investigation.

Gill said Thursday's charges focus only on Lawson.

"We are not looking at anybody else, other than our investigation is ongoing. When the rest of our investigation is completed, we'll address those issues, if necessary, at that time," he said.

Shurtleff did not immediately return a phone message seeking comment.

Lawson and Swallow have maintained a friendship since 2009, according to court documents. They have exchanged 680 calls or text messages, the latest being September, prosecutors say. They discussed the holidays, the 2012 election, the FBI investigation into Swallow and possible wiretapping of Lawson's phone.

Swallow's attorney Rod Snow questions that number and disagrees with the characterization that Swallow and Lawson have a longtime association. Swallow has tried to "steer clear" of Lawson and did not want him raising money for his 2012 election campaign as he had done for Shurtleff, he said.

Snow also said he doesn't see why Gill and Rawlings are "throwing that out there" when it's not relevant to the charges against Lawson.

Lawson represented himself as a close friend of Shurtleff's to businessman Marc Sessions Jenson, who faced securities fraud charges in 2008. Lawson emailed Shurtleff a proposed plea agreement for Jenson without knowledge of the prosecutor assigned to the case, according to court documents.

Shurtleff himself arranged a plea in abeyance for Jenson that the assigned prosecutor found so lenient that she told her superiors about it and then was removed from the case, court documents show. It contained neither jail time nor restitution.

A judge subsequently rejected the deal but approved an amended plea deal that had no jail time but included $4.1 million in restitution.

While on probation as part of the deal in 2009, Jenson paid Lawson $120,000 to gain access to Shurtleff and to influence potential witnesses or victim on Jenson's behalf, according to court documents. The charges state that Lawson failed to disclose the income or pay taxes on it.

Also at that time, Lawson arranged trips for Shurtleff and Swallow, who had yet to join the attorney's general's office, to the posh Pelican Hill Resort in Southern California where Jenson lived. Jenson paid for lodging as well as massages, golf, food and clothing. Jenson had not paid the $4.1 million court-ordered restitution at the time, and he ultimately failed to do so. He is now serving a 10-year prison sentence.

During one of those trips, Shurtleff told Jenson to give businessman Darl McBride $2 million to get McBride to take down a website attacking another prominent businessman, Mark Robbins, with whom McBride had an ongoing battle over a business deal gone bad, according to court documents.

Lawson allegedly told McBride that he would be sitting in jail for a long time because Shurtleff had "things" on him. He also said that he had guns and "Polynesian friends" who liked to "bust people up," according to court documents.

During a meeting with McBride at a Mimi's Cafe, Shurtleff acknowledged that Lawson used his name and told people that he represented the attorney general, court documents say. Shurtleff also explained that Lawson introduced him to people who became campaign contributors.

"During the conversation, Shurtleff acknowledged that Robbins was doing a 'Ponzi' scheme, but he wanted McBride to back off anyway," according to court documents.

Lawson also allegedly got involved in the failed billion-dollar development known as Mt. Holly Resort that Jenson and his brother, Stephen Jenson, tried to build in Beaver County. When the deal crumbled, a Colorado doctor who had invested in the project wanted his money back.

According to court documents, Lawson sent several aggressive text messages and emails to the doctor to dissuade him from providing testimony for any possible investigation or legal action. Lawson also threatened to reveal supposed illegal activity in the doctor's medical practice.